What is the easiest way to open macadamia nuts, should I roast or boil them first?

Class, do you know why macadamia nuts are so expensive?

Is it because the trees yield little fruit? No, macadamia trees produce generously. Is it because they’re exotic  native to Australia but grown mostly in Hawaii, so transportation costs are exorbitant? Transportation costs are a factor, certainly, but many nuts are tropical and include transportation in a more modest retail price. Is it because of their high fat content? No, pecans have a very high fat content, too, at a more sensible price. Is it because they’re so tasty? Partly, but there are lots of tasty nuts out there that cost less.

Now class, repeat after me, "macadamia nuts are outrageously expensive because it is so hard to open the shells without smashing the nuts to oblivion."

Macadamias have always been known for their extreme difficulty in shelling, as the shells are the hardest in the nut family. It takes 300 pounds per square inch of pressure to crack the shell. Yes, macadamia nuts in the shell can be anywhere from 40% to 85% cheaper than shelled nuts, but because they’re so hard to open, they are seldom available in the shell.

Sadly, we at Ochef once had a very embarrassing scene involving the attempted cracking of macadamia nuts outside in the dark of night that, well, we’d rather keep to ourselves. Suffice it to say that we’re not sure to this day where some of those nuts wound up.

We have seen a person in Hawaii nestle a macadamia nut in a crevice of a rough volcanic rock and hit it with another rock with just the right force to gently crack it open and remove the nutmeat  doubtless the result of a bit of trial and error.

Another Hawaiian says, "As children, we knew where and when to go out and gather these nuts. How did we open them? We found just the right sized hole in the curbings of the streets where we lived; it had to be just deep enough to hold the nut in place. A well-placed nut in the right sized recess will come apart fairly well when given a sharp blow with a hammer."

Finally, we know of one fellow who has a few trees of his own and sends his modest crop out for professional shelling rather than doing it himself.

Obviously a bench vise will allow you to open macadamia shells securely and safely, but the process will be slow.

Experiments in Hawaii have shown that roasting can be used to decrease the moisture in the shell below that of the kernel, which causes it to become brittle and easier to crack. We’ve heard good things about boiling, as well, but have never done it ourselves.

We have also come across three nutcrackers specially designed for the macadamia: